Abstract:The insect resistances and evaluations on important agronomic and economic characters of 6 Bt-transgenic sugarcane lines, such as Y2, Y3, Y4, T1, T2 and T3, were studied both in the field and room. The results showed that the insect resistances of these Bt-transgenic sugarcane lines in the field were similar to those in the room, and the Bt gene expression was stable. All of these tested lines had stronger insect-resistance than their wild types, in which Y4 and T2 lines were the strongest and T3 line was the weakest. The cane yield and sugar content in Y3, Y4 and T3 lines were similar to those in their relative original lines, but the sucrose content of these transgenic lines was lower than that in original lines. In addition, although T2 line had higher sucrose content than original line ‘ROC16’, its main agronomic traits were worse with low cane yield and sugar content.